Warning: Spoiler alert! Do not proceed if you haven't watched Monday's season seven premiere of Arrow.

A new generation of the Queen family has landed on Lian Yu.

In Arrow's season seven premiere on Monday, fans watched as the show's traditional flashback sequences were replaced by something else, someone else, as it were: the story of a mysterious stranger risking life and limb (and a substantial bank account, from the sound of it) to make his way to the infamous island in the North China Sea, where Oliver Queen (Stephen Amell) became the Green Arrow all those years ago. When he finally lands, he sets off on a mission of another kind, but it wasn't until the episode's final moments that we finally found out why he's come.

After being hunted down by a hooded archer, who turns out to be a weathered Roy Harper (Colton Haynes, returning to the role as a series regular this season), the man reveals he's not a stranger at all. He's William, Oliver's son. It's the future!

"We always knew, like, after season five there won't be flashbacks," showrunner Beth Schwartz told reporters of the big reveal, "so we had talked about doing flash-forwards a lot, years ago."

"Part of what I think made this series so successful in having the flashbacks is, you were able to really get into your characters, because you knew, especially with Oliver, you knew how he became the way he is," she added. "And now with the flash-forwards, you're able to see what is happening in our present day, how that affects our characters and the future which is really, really, really fun, creatively, to tell those stories."

On Sunday, at the The CW Fall Launch Event, in partnership with #SeeHer, Schwartz opened up further about the exciting story possibilities that the timeline presents, giving a sweet shout-out to another popular show that recently surprised fans with flash-forwards: This Is Us.

"I do love This Is Us, and Dan Fogelman was actually my first boss in Los Angeles, so he is the best person in the world," she raved. "But I’m a huge fan of that show and also Westworld in how they play with time. I think it’s so smart. As an audience member, I love watching that kind of storytelling."

When it comes to Arrow, Schwartz explained, "We’ve told the story for seven years of our characters and have they really helped the city [as] vigilantes -- are they good or are they bad? Now we’re able to see if their actions really helped in the future. That’s the cool part for us and really getting to know more mystery of like, what happened in that missing time is always good. Mystery on Arrow is key and that’s what I love about the show."

Last season, the DC Comics-inspired series continued using flashbacks to tell different stories about several of its main characters, but this year, the show is jumping about 20 years ahead to explore the mysterious circumstances that brought William to Lian Yu. Schwartz confirmed that, while the flash-forwards will not be present in every episode, they will explore a season-long story arc -- "We won’t just keep mysteries alive, we’ll answer them as well." -- while excitedly introducing series newcomer Ben Lewis, who plays the older William.

"I'm so excited to announce him because he's so great," she raved of the actor, previously known for roles on Chasing Life and Degrassi: The Next Generation. "He's a really good actor and that's another thing we've been doing a great job with keeping quiet."

The Arrow creative team was also excited to explore more of William's story via the timeline jumps, including how the trauma of growing up around vigilantes might affect him later in life. "We were always like, that kid’s had some bad times!" Schwartz told ET. "What does that look like when you’re an adult dealing with that? That was always something we talked about."

And while the flash-forwards have no correlation to other iterations of the future that Arrow 'verse fans have seen on CW's spinoff shows -- such as the Legends of Tomorrow's visit to Star City 2047 -- Schwartz played coy about which characters we might see aged up in the 2040 scenes, as well as whether or not Haynes will appear as Roy in the present-day storylines.

However, some mysteries will be solved sooner than later, such as the identity of the city's new Green Arrow, who has taken up the vigilante mantle while Oliver languishes behind bars in Slabside Maximum Security Prison -- and even has his very own list of targets. "We'll definitely unveil and explore [that] before the end of the season, for sure,'" Schwartz assured.

The theme of season seven is "redemption," and the executive producer noted that "it's going to affect all of our characters. Obviously, Oliver's character the most."

"In terms of everything he's done for the past six years and... because his identity is outed, which is, like, a huge series moment as well," she explained, "everyone knows who he is and that's going to be huge. He's going to have to deal with that all season as well. He no longer can hide behind the mask or prison or all those things."

As for life behind bars, Schwartz noted that things won't be getting much easier for Oliver in upcoming episodes, especially now that he has given up on his mission to keep his head down and avoid the angry antagonists among his fellow inmates.

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"He learns a lot while he's there, which is really cool," Schwartz said. "He was kind of different than we've ever seen him where he was not the hero and just laying low and thinking that was the best way for him to be in prison. Then obviously when his family gets attacked, he can't not be the Green Arrow... So he's going to continue to struggle with what does that look like, being the Green Arrow while you're behind bars? It's not easy."

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The showrunner also noted that Oliver, who "doesn't like not controlling things," will grapple the most with being locked up as villains like Diaz (Kirk Acevedo) and the Longbow Hunters wreak havoc on Star City. "He's on the inside while the Big Bad is out there. So that's been really hard on his character, but creatively, really interesting for us to play with. You'll have to see how our group manages to deal with that."

The premiere gave a look at how each of the team members has been handling life in Oliver's absence, most notably Felicity (Emily Bett Rickards), who was on the run and in witness protection program with his son, William (Jack Moore). But when Diaz proves that he can find them even through the layers of defensive government obfuscation, attacking and nearly killing them inside their safe house, Felicity decides to face the fight head-on, returning to Star City and reclaiming her heroic identity.

"We played her pretty parallel to Oliver, where she's hiding, she's not being herself," Schwartz explained. "She's in protective custody and then when someone attacks her family, she can't ignore that."

"She has to fight back, so she's going to figure out how do I fight back without my husband who happens to be the Green Arrow?" she added. "That will be her challenge in the first half this season."

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Felicity may or may not have the help of the rest of the team, as Schwartz noted that "everyone in our old team is trying to figure out what it means to them to be hero to the city." And she confirmed that Rene (Rick Gonzalez) is definitely the "most interested" in learning more about the new Green Arrow, after fans saw him suiting back up to help the vigilante escape capture in the season premiere.

"Rene definitely has the biggest struggle," she added. "Obviously, in the premiere, he got back in that Wild Dog outfit and he's... Everyone will kind of have a different opinion of getting back."

For Dinah (Juliana Harkavy), her new position as police captain has her questioning a return to the world of vigilante heroics. "She's kind of going back to her roots a little bit," Schwartz said of the former cop turned Black Canary. "We see in the premiere, she fully believes [in] the law now, she's now on the other side of things, which is what's so interesting. It's because, and Rene is calling her out on it, that she's now the people who used to chase after them, but she believes that what's best for the city is law and order and not necessarily vigilantes anymore."

Another original team member stepping away from the vigilante lifestyle is John Diggle (David Ramsey), who is now working for his wife, Lyla (Aubrey Marie Anderson), at A.R.G.U.S., "which I love," Schwartz noted.

"We'll see in the next few episodes how he's kind of dealing with what happened to Felicity," the producer said of the Green Arrow's former right-hand man. "He's kind of Oliver's brother, in a sense, and he obviously wants to protect Oliver's family. But he's full-time A.R.G.U.S. now, and so we'll see some A.R.G.U.S. stories, which is really fun."

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For the time being, he'll be sharing office space with Curtis (Echo Kellum), another former team member who seems more than happy to be away from the heroic life and back in front of his familiar screens. "We're going to see that Curtis was a little more traumatized than we thought from how things went down last season," Schwartz noted. "Which is why he specifically chose his position in ARGUS. That'll come out this season."

However, the hardest transition may still be to come for Laurel Lance (Katie Cassidy), who is working to fill the shoes of her late Earth-1 counterpart and complete her journey from villain to hero.

"She has kind of the farthest to redeem herself," Schwartz said, calling back to the season's theme. "She's the D.A. as we saw in the premiere, but she is sort of, her season-long arc is about, is she Laurel or is she Black Siren?"